Merge pull request #1 from iaminsharingcode/master

Fix can change status & value when has been fulfilled / rejected
yanguango · Apr 14, 2020 · 2a0aa80 · 2a0aa80
2 parents 4b88e17 + ee53366
commit 2a0aa80
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Showing 2 changed files with 20 additions and 0 deletions.
diff --git a/dist/src/promise.js b/dist/src/promise.js
@@ -27,7 +27,13 @@ class Promise {
     executor(this._resolve.bind(this), this._reject.bind(this));
   }
 
+  _hasResolved() {
+    return this._isFulfilled() || this._isRejected();
+  }
+
   _resolve(x) {
+    if (this._hasResolved()) return;
+
     if (x === this) {
       throw new TypeError("Resolving object can not be the same object");
     } else if (x instanceof Promise) {
@@ -58,12 +64,16 @@ class Promise {
   }
 
   _fulfill(result) {
+    if (this._hasResolved()) return;
+
     this._state = State.Fulfilled;
     this._value = result;
     this._handlers.forEach(handler => this._callHandler(handler));
   }
 
   _reject(error) {
+    if (this._hasResolved()) return;
+
     this._state = State.Rejected;
     this._value = error;
     this._handlers.forEach(handler => this._callHandler(handler));

diff --git a/src/promise.js b/src/promise.js
@@ -22,7 +22,13 @@ export class Promise {
     executor(this._resolve.bind(this), this._reject.bind(this));
   }
 
+  _hasResolved() {
+    return this._isFulfilled() || this._isRejected()
+  }
+
   _resolve(x) {
+    if (this._hasResolved()) return
+
     if (x === this) {
       throw new TypeError("Resolving object can not be the same object");
     } else if (x instanceof Promise) {
@@ -57,12 +63,16 @@ export class Promise {
   }
 
   _fulfill(result) {
+    if (this._hasResolved()) return
+
     this._state = State.Fulfilled;
     this._value = result;
     this._handlers.forEach(handler => this._callHandler(handler));
   }
 
   _reject(error) {
+    if (this._hasResolved()) return
+
     this._state = State.Rejected;
     this._value = error;
     this._handlers.forEach(handler => this._callHandler(handler));